Targeted molecular imaging of cancer is vital for better personalized medicine, but requires novel imaging agents that recognize key molecular surface cell markers. Her2 is overexpressed in 20-30% of breast cancer and is targeted by Herceptin, yet no molecular imaging agent for Her2 is clinically approved. We propose to use Scanning Unnatural Protease Resistant (SUPR) peptides to develop a novel Her2-specific radiotracer for PET/CT. SUPR peptides show antibody-like affinities, resistance to proteolytic and metabolic modification, and rapid clearance from systemic circulation, making them ideal imaging agents. First, Anti-Her2 SUPR peptides modified with a near-infrared optical dye will be screened for Her2-specific tumor uptake mice. We will then synthesize [18F]-labeled SUPR peptides to image Her2-overexpressing tumors by PET/CT. EvoRx Technologies will collaborate with the MD Anderson Cancer Center to rapidly translate SUPR peptides into a powerful nuclear imaging tool, advancing the personalized treatment of breast cancer.